IPv6 - Blocks, Slashes and Big Numbers

IPv4 addresses are 32-bit while IPv6 addresses are 128-bit. Customers can get a /64 allocation of IPv6 addresses provisioned to a single SoftLayer server. A /64 block of IPv6 addresses contains 18,446,744,073,709,551,616 distinct addresses. The entire IPv4 address space is 4,294,967,296 distinct addresses.

It's easy to get lost in a sea of numbers when you start talking about IPv4 and IPv6 address space. With the exhaustion of IPv4 address space and the big push toward IPv6, everyone's talking about address blocks, usage justification and dual stack compatibility, but all of those conversations presuppose a certain understanding of why IP addresses are the way they are. Someone can say, "The IPv6 pool is exponentially larger than the IPv4 pool," but that statement needs a little context when you hear that providers like SoftLayer are provisioning a free /64 IPv6 allocation of 18,446,744,073,709,551,616 addresses to a single server. If the entire IPv4 pool on the Internet is 4,294,967,296 addresses and we're giving away that many IPv6 addresses to a single server, a simple question logically follows:

Are the Internet authorities being irresponsible when they're allowing such huge numbers of IPv6 addresses to be assigned to individual servers without a demonstrated need for that many addresses? Will this "wastefulness" lead to another IP address pool depletion in our lifetime? These questions are completely legitimate, and they're much easier to explain in a visualized format than they are if we answered them line-by-line in text:

The video duration might seem intimidating, especially if you consider that all 15 minutes are spent talking about IP addresses (Woohoo!), but there's a lot of information, and we did our best to break it down to simple pieces that logically follow each other to help you get the full picture of the world of IP addresses. We explain what CIDR Slash (/) Notation (where you see IP address blocks written as "192.0.2.0/24"), and we offer a simple trick to calculate the number of distinct addresses available in a given IPv4 block. There's a fair amount of witty (and not-witty) banter and at least one use of the word "ridonkulous," so if you enjoyed the DC Construction video commentary, you'll get a kick out of this one too.

Comments

Love the presentation and the geeky but lucid way the IPV6 concept has been explained to the uninitiated like me :) Can you also let me know why IPV6 adoption is slow. Are all ISPs and networking equipment not supporting IPV6 addresses yet?

Full adoption of IPv6 will almost certainly take many years but I think in the next 3-5 years we'll probably see logarithmic adoption as it will simply be a necessity if the Internet is to expand, as it surely will. There's also a huge amount of unused IPv4 space going out for sale on the open market. Many many providers and big corporations got massive IPv4 space allocations in the early days of the Internet and are only using a small fraction of it so even though IPv4 space is "exhausted" and IANA and other registries cannot allocate new IPv4 space there is still a ton that is not in use. There are many millions of legacy IPv4 devices - i.e. the millions of home wireless routers out here. That said many even basic home wireless routers released in the last year or two are IPv6 capable and corporate Cisco, Juniper, Huawei, Brocade, etc. routers have been IPv6-capable for several years now . Comcast is transitioning to IPv6 right down to the home cable modem and will tunnel IPv4 into IPv6. All or nearly all major backbone ISPs are fully IPv6 capable and probably running dual-stack IPv4/IPv6. Many enterprises are migrating their core networks to IPv6 and running dual-stack on their servers. Percentage-wise it's relatively small but it's happening.

The HTML/CSS reference in the video was more of an "off-the-cuff" realization than a declarative statement, and I think you're right about that.

We should have given an example of CIDR notation when we started explaining it, and now that you mention it, that omission is pretty glaring. It's been about a year since we made the video, so it's about time to refresh the content to make it even smoother ... We'll probably script it out a little more as well.

I'm not sure whether Internet-enabled appliances like televisions and refrigerators use a standardized network configuration, but I'd certainly hope they're using NAT or self-assigned IPs behind a router ... With IPv4, providing a public IP address to each would be problematic, but with IPv6, it'd be less so.

Wow, thanks for this very cool video on IPv6. I just got a VPS that gave me /64 IPv6 addresses and didn't quite understand what it meant. I found you guys through a google search for this and am so glad you spelled it out for me!

Within even SoftLayer, how would one utilize even a few of these addresses? The only scenario I can think of is assigning a large number of IPv6 addresses to just one machine. But this wouldn't necessarily provide any sort of performance boost. It would just allow that one machine to be accessed via several different IPv6 addresses.

why is ipv6 so slow to adoption? because 4 octets of numerals is way easier to remember. even tech people that can remember a lot dont want to go through that. were all dragging tooth and nail until its eventual. however, they said the world would blow up years ago because of ipv4 running out of addresses.

What's with the other guy who just repeats things that the main guy is saying. Incredibly annoying. I stopped the video after a minute cause I couldn't handle it. Cool graphics, but I wish the video had only one person talking in it. Sorry.

Comments

Love the presentation and the geeky but lucid way the IPV6 concept has been explained to the uninitiated like me :) Can you also let me know why IPV6 adoption is slow. Are all ISPs and networking equipment not supporting IPV6 addresses yet?

Full adoption of IPv6 will almost certainly take many years but I think in the next 3-5 years we'll probably see logarithmic adoption as it will simply be a necessity if the Internet is to expand, as it surely will. There's also a huge amount of unused IPv4 space going out for sale on the open market. Many many providers and big corporations got massive IPv4 space allocations in the early days of the Internet and are only using a small fraction of it so even though IPv4 space is "exhausted" and IANA and other registries cannot allocate new IPv4 space there is still a ton that is not in use. There are many millions of legacy IPv4 devices - i.e. the millions of home wireless routers out here. That said many even basic home wireless routers released in the last year or two are IPv6 capable and corporate Cisco, Juniper, Huawei, Brocade, etc. routers have been IPv6-capable for several years now . Comcast is transitioning to IPv6 right down to the home cable modem and will tunnel IPv4 into IPv6. All or nearly all major backbone ISPs are fully IPv6 capable and probably running dual-stack IPv4/IPv6. Many enterprises are migrating their core networks to IPv6 and running dual-stack on their servers. Percentage-wise it's relatively small but it's happening.

The HTML/CSS reference in the video was more of an "off-the-cuff" realization than a declarative statement, and I think you're right about that.

We should have given an example of CIDR notation when we started explaining it, and now that you mention it, that omission is pretty glaring. It's been about a year since we made the video, so it's about time to refresh the content to make it even smoother ... We'll probably script it out a little more as well.

I'm not sure whether Internet-enabled appliances like televisions and refrigerators use a standardized network configuration, but I'd certainly hope they're using NAT or self-assigned IPs behind a router ... With IPv4, providing a public IP address to each would be problematic, but with IPv6, it'd be less so.

Wow, thanks for this very cool video on IPv6. I just got a VPS that gave me /64 IPv6 addresses and didn't quite understand what it meant. I found you guys through a google search for this and am so glad you spelled it out for me!

Within even SoftLayer, how would one utilize even a few of these addresses? The only scenario I can think of is assigning a large number of IPv6 addresses to just one machine. But this wouldn't necessarily provide any sort of performance boost. It would just allow that one machine to be accessed via several different IPv6 addresses.

why is ipv6 so slow to adoption? because 4 octets of numerals is way easier to remember. even tech people that can remember a lot dont want to go through that. were all dragging tooth and nail until its eventual. however, they said the world would blow up years ago because of ipv4 running out of addresses.

What's with the other guy who just repeats things that the main guy is saying. Incredibly annoying. I stopped the video after a minute cause I couldn't handle it. Cool graphics, but I wish the video had only one person talking in it. Sorry.